Year	Number
1970	57700000
1971	62500000
1972	64300000
1973	65800000
1974	67500000
1975	68800000
1976	69700000
1977	70700000
1978	71300000
1979	70000000
1980	73000000
1981	72700000
1982	73000000
1983	72900000
1984	73200000
1985	72700000
1986	72900000
1987	72800000
1988	72100000
1989	71200000
1990	70400000
1991	70400000
1992	70700000
1993	72000000
1994	73000000
1995	73100000
1996	73200000
1997	70400000
1998	75300000
1999	75200000
2000	76400000
2001	76900000
2002	77600000
2003	78600000
2004	76800000
2005	77300000
2006	77900000
2007	77700000
2008	77700000
2009	77400000
2010	77100000
2011	76700000
2012	76500000
2013	77200000
2014	77100000
2015	77100000
2016	76800000
2017	76700000
2018	76100000